Organic light emitting diodes (OLEDs), due to their characteristics such as self-luminous property, quick response, rich colors and the like, have gradually become important display devices. In the prior art, an OLED array substrate has a complicated structure, and generally includes structures of thin film transistors and OLEDs, wherein various structures, such as gates, sources and drains of the thin film transistors and cathodes and anodes of the OLEDs, need to be formed by many patterning processes. As a result, manufacturing process of the OLED array substrate is complicated.
In addition, it is extraordinarily important to form an even and stable organic light emitting material layer in an OLED. Especially in the case of using an inkjet printing technique, defects such as Mura may occur once an ink droplet of the organic light emitting material fails to spread evenly in an ink droplet accommodation unit. This may decrease yield of OLED array substrate products.